Jack was just keeping a wary eye on this teenager (a perfectly normal head-mounted one, not the weird one in his chest), very carefully trying to drink his cup of coffee with a mouth that was not designed for coffee drinking. He was just going to let Hajime field this one... until the kid started blabbing about the network. Then he lowers the cup of coffee and speaks.

"We came for pancakes, as well." Well. He did. Hajime came because the family that makes poor life choices together stays together. Or something. "Don't be too jealous, or you might wake up one morning looking like this." It wasn't an outright confirmation of the whole network thing, but hopefully it was close enough to one for the drunk kid to get.